Arrangement for break-separating bearing covers of aligned bearing bores in bearing device of a machine member

ABSTRACT

For a device for fracture separating bearing covers of aligned bearing bores in bearing arrangements of a machine member, which comprises a guided separating element which is profiled in an approximately semicircular shape and acts in the center onto a bearing cover in the bearing bore, for obtaining a device which is structurally simple, it is suggested that, for the fracture separating, a half-mandrel or full mandrel, which can be axially arranged in one or several bearing bores, is provided. An operating linkage, which only causes the guiding of the respective mandrel in the fracture separating direction, is applied to the respective mandrel transversely to its longitudinal course, the respective mandrel being held in a rotationally secured manner and each bearing cover being rotationally secured while being clamped against the respective mandrel.

BACKGROUND AND SUMMARY OF THE INVENTION

This invention is based on the preamble of claim 1 of U.S. PatentDocument U.S. Pat. No. 4,684,267.

This known device, which can be used for several bearing arrangements ofa crankcase of a piston engine, serves the purpose of a step-by-stepfracture separating of the bearing covers which are cast in one piecewith the crankcase. For this purpose, this known fracture separatingdevice comprises a cylindrical supporting body which can be introducedinto the bearing bore of several bearing arrangements and hastransversely directed cuts provided in the spacing of the bearingarrangements with respect to the respective guided arrangement of aseparating element designed approximately in the shape of half a disk.Recesses in the supporting body and the separating elements, which areprovided in the center in the longitudinal course, are used forreceiving an operating rod for the separating elements. The operatingrod, which is operatively connected with an energy accumulator, haswedge surfaces assigned to the separating elements for the radialdisplacement of the separating elements in the bearing bores forgenerating fracture separating forces.

This known device, which comprises a guidance of each separating elementwhich is separate from the operating rod, has the disadvantage of aproportion of frictional force which is high relative to the sum of allfracture separating forces and which, in addition to the energyaccumulator with correspondingly large dimensions, also results in highexpenditures with respect to energy. The frictional forces in the knowndevice, which are in effect on the wedge surface pairs of the operatingrod and the separating elements, also result in a wear of a varyingdistribution which acts against an advantageous, virtually one-stepbreaking operation in the case of each bearing cover. On the contrary,this results in a time-staggered breaking of the bearing covers withresulting fracture separating surfaces of varying qualities because, forlater-breaking bearing covers, the unchanged total fracture separatingforce is distributed to a few residual bearing covers. Furthermore, inthe case of this known fracture separating process, the bearing coversare first fracture-separated from the crankcase on one side,specifically in an uncontrolled manner, and, for the fractureseparating, for avoiding a bending breakage, the fracture-separated sideof each bearing cover is rotationally secured by high-expenditureadditional measures, for example, by means of screws.

A device for fracture-separating bearing covers with a relativelyfavorable ratio of the proportion of the frictional force of the deviceto the fracture separating force to be applied is known from EuropeanPatent Document EP-B 0 396 797. In the case of this device used for thefracture separating of connecting-rod bearing covers, the operatinglinkage is a falling impact mass for affecting a guided carriage onwhich a half-mandrel is arranged which penetrates the bearing covers ofthe rotationally secured connecting rod and is fixedly connected withthe carriage on both ends. In this case, the guided carriage is used forguiding the half-mandrel affecting the bearing cover for the purpose offracture separating.

In the case of this device with a guidance of thefracture-separating-effective half-mandrel, it is also a disadvantagethat the impact mass acting as the operating linkage springs backbecause of the material elasticities when impacting on the pushedcarriage used for guiding the half-mandrel, and therefore, during thefracture separating operation, the impact mass and the carriage do notconstantly act in the same direction. In a disadvantageous manner,fracture surfaces of formed cracks may strike on one another in aswinging manner and cause a breaking-out of materials.

Finally, another device is known from U.S. Patent Document U.S. Pat. No.4,754,906 which is used for the fracture separating of a connecting rodbearing cover and has a guidance for a fracture-separating-effectivehalf-mandrel which is separate from the operating linkage. Thishalf-mandrel, which is arranged in a relatively movable manner in astand, is acted upon hydraulically. It comprises a chamber for ahydraulic operating linkage in which a piston-type extension, which issupported against a half-mandrel fixedly arranged on the stand, engagesas a support of a sealing device.

The relatively massive, fracture-separating-effective half-mandrel isguided on the stand side by way of guiding surfaces spaced away from thepiston-type chamber extension or from the plane of the introduction ofthe fracture separating force. Particularly as the wear of the guidingsurfaces increases, this arrangement seems critical because, during theforce-controlled impacting of the half-mandrel against the bearing boreof a connecting rod bearing arrangement, an oblique positioning cannotbe excluded with results in additional friction. However, an obliquepositioning has a disadvantageous effect on the fracture separating.

It is an object of the invention to design a device for fractureseparating such that a relatively low proportion of friction forceremains low for a long usage time of the device as a result of a simplerstructure of the device and such that the device structure permits adesired massive construction of the device, while the space requirementsare relatively low, for a force which can be abruptly set free from arespective energy accumulator and which, acting as an active forcedirectly on the bearing cover to be separated, is intended for a perfectone-step fracture separating of a bearing cover which is held in arotationally secured manner by means of the device.

This object is achieved by means of claim 1, the inventive design of thedevice for fracture separating being characterized in that, for thefracture separating, a half-mandrel or full mandrel which can be axiallyarranged in one or several bearing bores is provided, and in that anoperating linkage, which exclusively causes the guiding of therespective mandrel in the fracture separating direction, is applied tothe respective mandrel transversely to its longitudinal course, in whichcase the corresponding mandrel is held in a rotationally secured mannerand each bearing cover is rotationally secured while being clampedagainst the respective mandrel.

The inventive combination of the characterizing features advantageouslyresults in a simpler structure of the device, in which case, incomparison to the prior art, the simpler structure, in a manner which issignificant with respect to the invention, is achieved by means of acombined operating/guiding linkage which is applied to the respectivemandrel transversely with respect to its longitudinal course in thefracture separating direction. By means of the integration according tothe invention of the mandrel guidance required for a perfect fractureseparating with the operating linkage, the number of guiding surfacessubjected to friction is considerably reduced. The advantage is africtional force proportion to be generated by the energy accumulatorwhich is lower relative to the fracture separating force. This has theadditional advantage of a smaller-size energy accumulator and, becauseof the lower friction loss for an abrupt introduction of force,advantageously results in an almost vertical course of the rise of forcein the case of a corresponding selection of an energy accumulator.

By means of the selection of an energy accumulator in the preferredconstruction of a piston cylinder-unit with a piston rod which forms asection of the operating linkage, in a further advantageous manner, asimple construction of the structure of the invention is achieved inthat the piston rod which is guided in a straight manner on the cylinderside is used for the straight guiding of the respective mandrel in thefracture separating direction. This fracture separating device which, incomparison to the prior art, according to the invention, has a minimumof guiding surfaces with respect to its structure, irrespective of thenumber of the bearing covers to be fracture-separated, in addition tohaving a simple construction, it can be designed to be advantageouslymassive for a one-step fracture separating.

A particularly massively constructed operating linkage canadvantageously be used for the rotationally securing arrangement of therespective fracture separating mandrel. In a further advantageousmanner, the massively designed operating linkage permits the arrangementof a clamping device for a bearing cover which is operated in acontrolled manner, in which case the clamping device is brought to restagainst the assigned bearing cover before the fracture separating insuch a manner that the bearing cover is clamped in a rotationallysecured manner between the clamping device and the respective fractureseparating mandrel during and after the fracture separating in order toavoid a bending fracture in a last-breaking separating area.

The combined operating/guiding linkage which is guided in a straightmanner and has a fracture separating mandrel which is rotationallysecured relative to the operating/guiding linkage and has bearing coverswhich can be clamped in a rotationally secured manner relative to thefracture separating mandrel, is therefore advantageously distinguishedby the avoidance of influences which, in the operation of the device maybe disadvantageous for the one-step fracture separating (obliquepositioning, large plays, elasticities of materials).

In addition to the preferred piston-cylinder unit, falling weights areconceivable as energy accumulators for triggering the fracture in thecase of a corresponding prestressing force, and furthermore, a modifiedoperating linkage with a kinematically separately caused straightguidance of its connection point with the respective fracture separatingmandrel is also conceivable.

For a fracture separating device, which is massively structured whileits construction is compact, a hydraulic piston-cylinder unit ispreferred as an energy accumulator by means of which a desirably highprestressing force and, by means of a hydraulic intensification, afracture separating force which can be set free abruptly can byimplemented.

Advantageous embodiments of the invention are described in additionalsubclaims. In particular, these describe fracture separating mandrelswhich are designed with a view to different possibilities of introducingthe reaction force, which is diametrical to the fracture separatingforce, into the respective machine member, and fracture separatingdevices which by means of these mandrels are in each case adapted withrespect to the construction and the arrangement. Additional subclaimsrelate to applications of the fracture separating devices according tothe invention with respect to the number and arrangement of severalbearing covers to be separated, also with respect to relativearrangements of fracture separating surfaces of a bearing cover andfinally with respect to the handling of fracture-separated bearingcovers of one or several machine members.

Other objects, advantages and novel features of the present inventionwill become apparent from the following detailed description of theinvention when considered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of a schematic part sectional basic construction of afracture separating device according to a first preferred embodiment ofthe invention for fracture separating a bearing cover of a crankshaftbearing, which is cast integrally with a crankcase, by means of ahalf-mandrel;

FIG. 2 is a schematic part section view of a fracture separating devicefor the common fracture separating of several crankshaft bearing coversof a crankcase by means of a massive full mandrel, constructed accordingto a second preferred embodiment of the invention;

FIG. 3 is a schematic part sectional view of the FIG. 2 embodiment takenalong a plane perpendicular to the plane of the FIG. 2 illustration;

FIG. 4 is a schematic part sectional view of a device for the commonfracture separating of several crankshaft bearing covers by means of afull mandrel constructed of sections which can be radially moved withrespect to one another constructed according to a third preferredembodiment of the invention;

FIG. 5 is a schematic part sectional view of the FIG. 4 embodiment takenalong a plane perpendicular to the plane of the FIG. 4 illustration;

FIG. 6 is a schematic part sectional view of a fracture separatingdevice for the common fracture separating of several crankshaft bearingcovers by means of a full mandrel constructed of hydraulicallyexpandable halves, constructed according to a fourth preferredembodiment of the invention; and

FIG. 7 is a schematic part sectional view of the FIG. 6 embodiment takenalong a plane perpendicular to the plane of the FIG. 6 illustration.

DETAILED DESCRIPTION OF THE DRAWINGS

A device 1 is shown in FIG. 1 for fracture separating a bearing cover 3of aligned bearing bores 4 in bearing arrangements 5, which bearingcover 3 is integrally cast with a crankcase 2. Device 1 is structurallyformed of a fracture separating device 6 and a stand 7, which is notshown in detail and has a receiving device 8 for a crankcase 2. Thefracture separating device 6 comprises a combined operating/guidinglinkage 9 which is in an operative connection with an energy accumulatordesigned as a hydraulic piston-cylinder unit 10, for causing apredetermined prestressing force as well as the fracture separatingforce on the bearing cover 3.

For fracture separating the bearing cover 3 from the crankcase 2, thecombined operating/guiding linkage 9 interacts with a half-mandrel 11which can be axially arranged on the bearing cover side in the bearingbore 4. The half-mandrel 11, which is axially introduced into thebearing bore preferably in a mechanical manner, is connected with lugs12 positioned on both sides of the bearing arrangement, which lugs areconnected with a piston rod 14 of the piston-cylinder unit 10 by way ofan intermediate piece 13. The lugs 12 have openings 12' which correspondto the cross-section of the half-mandrel 11 and are adapted with aslight play and which therefore, at the same time, have the purpose ofrotationally securing the half-mandrel 11 relative to the direction ofthe fracture separating force according to the arrow "A".

According to the invention, the linkage 9, which by way of the lugs 12is applied to the half-mandrel 11 transversely to its longitudinalcourse, is also used for guiding the half-mandrel 11 used for thefracture separating in the fracture separating direction according toarrow "A". The straight-guidance of the half-mandrel 11 in the fractureseparating direction, which is advantageous for a more or less one-stepfracture separating of the bearing cover 3, is achieved in a simplemanner by means of a cylinder-side guide 15 of the piston rod 14 in thepiston-cylinder unit 10. The operating/guiding linkage 9 combinedaccording to the invention, while taking into account the slightdisplacement of the half-mandrel 11 customary during fractureseparating, therefore results in a fracture separating device 6 with africtional force proportion which is advantageously low in comparison tothe fracture separating force. The thus achieved favorable efficiencypermits the use of a small-size energy accumulator, such as thepreferably hydraulic piston-cylinder unit 10.

While the construction of the fracture separating device 6 isadvantageously compact, the operating/guiding linkage 9 according to theinvention also permits a massive further development of the linkage 9with massive lugs 12 for avoiding elasticities of material which mayhave an advantageous effect on the one-step fracture separatingoperation.

With the most extensive elimination of elasticities of material, atension-resistant operating/guiding linkage 9 is obtained which permitsa prestressing force from the hydraulic piston-cylinder unit 10 which isaimed at the quality of the machine member to be broken and which is by10 to 30% lower than the fracture separating force. A slight differencebetween the prestressing force and the fracture separating force isadvantageous for a one-step fracture separating of the bearing cover 3.In the case of a hydraulically intensified force acting upon the piston17 of the energy accumulator 10 initiated advantageously rapidly bymeans of a stepped piston 16, a slight difference between the two forcesresults in a very steeply rising course of the fracture separating forcefor the desired one-step fracture separating of the bearing cover 3 fromthe crankcase 2.

Another important aspect for achieving a one-step fracture separating ofthe bearing cover 3 is its rotational securing during the fractureseparating operation. Since, even if the fracture separating force isintroduced into the bearing cover 3 exactly in the center, a uniformbreaking in both separating areas of the bearing cover 3 and thecrankcase 2 is improbable because of inhomogeneities of the crankcasematerial, after a fracture in one of the separating areas, during thefurther separating operation, a rotation of the bearing cover 3 willoccur about the other separating area which has not been separated. Inorder to avoid this rotation, which is damaging to the quality of thefracture separating surfaces of a separating area, the bearing cover 3is rotationally secured by means of a stop 18 which is preferablyhydraulically operative in a controlled manner and may be locked (notshown).

The operating/guiding linkage 9 combined according to the inventionadvantageously permits the integral arrangement of the hydraulic stop 18in the linkage 9, whereby a clamping holding of the bearing cover 3 onthe half-mandrel 11 is ensured during the fracture separating operationand beyond. This integral arrangement of the stop 18 arranged in aguided manner in the intermediate piece 13 fixedly connected with thelugs 12 permits, in an inventive combination with the half-mandrel 11rotationally secured by way of the openings 12', relative to the lugs12, a clamping holding of the bearing cover 3 with an action/reactioneffect achieved in a massive section of the linkage 9 whichadvantageously has no influence on the guidance 15 of the piston rod 14of the linkage 9.

For a targeted initiation of the fracture, the bearing bore 3 ispreferably constructed with known fracture separating notches 19. Thesewill be sufficient for a fracture separating of the bearing cover 3 bymeans of the device 1 with fracture separating surfaces arranged on bothsides of the bearing bore 4 in a plane. In the case of fractureseparating surfaces according to application P 44 13 255, on which thepriority is based, which are arranged in a sloped manner with respect toone another, steps 20, which also influence the fracture breakingdirection, are assigned to the fracture separating notches 19. In thiscase, the design of the half-mandrel 11 is important whose curvatureradius in the area of the support in the bearing bore 4, as a functionof the respective angle α (not shown) between the mutually slopedfracture separating surfaces of a bearing cover 3, is selected to be0.5% to 5% smaller than the constant curvature radius of the bearingbore 4.

For the assignment to the respective bearing arrangement 4, which isrequired after the fracture separating for each bearing cover 3, eachbearing cover 3 is held loosely on the crankcase 2 by means of screwbolts which are not shown. In the case of mutually sloped fractureseparating surfaces with fastening screws which each extendapproximately vertically thereto, during the fracture separating, such abearing cover 3 is held loosely on the crankcase 2 by means of specialscrew bolts which have tapered shafts. These shaft taperings, incombination with the screw bolt passage bores (not shown) in therespective bearing cover 3, have the result that this bearing cover 3can be displaced to a sufficient extent in the fracture separatingdirection during the fracture separating.

The devices for fracture separating illustrated in the other figures arebased in principle on the device 1 of FIG. 1 but are further developedfor the simultaneous fracture separating of several bearing covers of acrankcase, preferably for the fracture separating of a bearing covercompound frame in which the bearing covers are fixedly connected withone another.

In the case of the device 21 illustrated in FIGS. 2 and 3, the combinedoperating/guiding linkage 22 comprises one lug 26 respectively betweenadjacent bearing arrangements 23 of a crankcase 24, which lug 26 isoperatively connected with the piston-cylinder unit 25. These lugs 26,which are connected with the piston-cylinder unit 25 by way of a commontension bar 28, have openings 29, which can in each case be aligned withthe bearing bores 27 of the bearing arrangements 23, for the guidedreceiving of a full mandrel 30 which can be introduced in the axialdirection of the bearing bores 27. Further, the fracture separatingdevice 31, which is essentially formed of the combined operating/guidinglinkage 22 and the piston-cylinder unit 25 (energy accumulator), isarranged in a stand 32 which has a receiving device 33 for thepositioned arrangement of the crankcase 24 relative to the fractureseparating device 31.

As illustrated particularly in FIG. 3, the fracture separating device 31has lugs 26 between the bearing arrangements 23 as well as outside theend bearing arrangements 23', which lugs are stressed with respect totension for prestressing and for the fracture separating force andwhich, being jointly operated by the piston-cylinder unit 25 supportedon a stand bar 32', act by way of the full mandrel 30 onto thefracture-separable bearing covers 34. For the rotationally secureholding of the bearing covers 34, stops 35 are provided on the lugswhich can be applied in a controlled manner to the bearing covers 34.FIG. 3 also shows that the full mandrel 30 strikes by means of an impactcollar 36 axially against an outer lug 26 and that the full mandrel 30is axially secured in its position in a clamped manner by means ofhydraulic pistons 37 impacting in the bearing bores 27 of the bearingarrangements 23.

Finally, the full mandrel 30, which, for example, can be deliveredmechanically, for achieving a fracture separating of predeterminedbearing covers 34 which is different with respect to time, may have, inits bearing-cover-side circumferential area, profiles which, inparticular, are offset in a radially eccentric manner, by way of whichprofiles bearing covers 34 which are assigned to same are brokensomewhat later.

As illustrated in FIG. 2, the fracture separating force in the case ofthe device 21, which is caused as a tension force by way of the fractureseparating device 31, is supported by way of the receiving device 33 ofthe stand 32. It is also shown that the bearing covers 34 are combinedto form a bearing cover compound frame 38. In order to facilitate thepositioning of the crankcase 24 relative to the fracture separatingdevice 31, the stand 32 is equipped with supporting receiving devices 39for the crankcase 24 which are arranged so that they can be movedtransversely with respect to the fracture separating direction.

A device 40 which is illustrated in FIGS. 4 and 5 is also used forfracture separating several bearing covers 42 for bearing arrangements43 of a crankcase 44 arranged in a bearing cover compound frame 41. Withrespect to its structure, the device 40 comprises a stand 45 and afracture separating device 46. Relative to the fracture separatingdevice 46 causing the fracture separating by tension, the crankcase 44is positioned on supporting receiving devices 47 of the stand 45 whichcan be moved transversely. Deviating from the device 21 of FIGS. 2 and3, in the case of the device 40, the fracture separating force isintroduced into the crankcase 44 not from the outside but, by way ofsupporting lugs 48 fixed to the stand, directly into the bearing boresof the bearing arrangements 43 of the crankcase 44.

Relative to the bearing arrangements 43 of the crankcase 44, thesupporting lugs 48 are arranged such that one tension lug of thecombined operating/guiding linkage 50 is arranged between two supportinglugs 48 respectively. The lugs 49 are jointly operated by apiston-cylinder unit 51 of the fracture separating device 46. By meansof the different type of support of the fracture separating force, abuilt-up full mandrel 52 is obtained for the fracture separating device46.

The built-up full mandrel 52 comprises a carrying mandrel 53 on whichsupporting sleeves 54 are arranged which are alternately centered in thesupporting lugs 48 as well as fracture separating sleeves 55 which arecentered in the tension lugs 49. The fracture separating sleeves 55 arearranged to be movable in the fracture separating direction relative tothe carrying mandrel 53 and, by means of axially extending,semicircular-type extensions 55', engage in adjacent bearingarrangements 43 for acting upon bearing covers 42 which can be fractureseparated. The supporting sleeves 54 which are centered in thesupporting lugs 48 have axially extending semicircular-type projections54' by means of which the reaction force, which is diametrical withrespect to the fracture separating force, is introduced into therespective bearing bore of a bearing arrangement 43 in a circumferentialarea which is diametrical with respect to the bearing cover 42 which canbe fracture-separated. Thus, the fracture separating forces aresupported in the bearing bores of the bearing arrangements 43 and arethus kept away from other parts of the crankcase 44.

The full mandrel 52, which is built-up to essentially fill out by meansof an expediently selected play the respective bore cross-sections inthe lugs 48 and 49 as well as in the bearing arrangements 43 by means ofits fracture separating sleeves 55 and supporting sleeves 54, isarranged in a rotationally secured manner on one of the supporting lugs48 in which case, for the precise alignment of the fracture separatingsleeves 55 in the fracture separating direction, the supporting sleeves54 are non-rotatably connected with the carrying mandrel 53 of the fullmandrel 52. As also shown in FIG. 5, the supporting sleeves 55 areguided in sections on the front side between the supporting sleeves 54which are non-rotatably arranged on the carrying mandrel, in which casethis guidance is also promoted by the fact that each fracture separatingsleeve 55 is operated by way of a tension lug which acts on an axiallyrelatively wide basis.

In addition, the device 40 is equipped, on the massive tension lugs 49of the combined operating/guiding linkage 50, with rotationally securingstops 56 (schematically illustrated) which can be applied in acontrolled manner.

A device 57, which is illustrated in FIGS. 6 and 7, comprises withrespect to its structure also a stand (not shown) for the positioning ofa crankcase 58 with integral bearing arrangements 59 whose bearingcovers 60 are separated by means of a fracture separating device 61. Thefracture separating device 61 comprises an expanding mandrel 62 whichcan be axially introduced through all bearing bores of the bearingarrangements 59 and which is formed of two half-mandrels 63, 64. In thiscase, the bearing-cover-side half-mandrel 63 is used for the fractureseparating of the bearing covers 60, which half-mandrel 63 is supportedwith respect to the housing-side half-mandrel 64 against the resistanceof an elastically flexible stop 65 by way of hydraulic pistons 67 usedas a combined operating/guiding linkage 66.

For achieving an operating/guiding linkage 66 of a simple construction,the hydraulic pistons 67 are made of commercially available clampingstrips which are arranged to be guided in oblong-hole-type chambers 68of the case-side or the supporting-side half-mandrel 64. So that, for aperfect fracture separating of the bearing covers 60, when pressure isadmitted to the chambers 68, the two half-mandrels 63, 64 are guidedexactly in parallel to one another, the bearing-cover-side half-mandrel63 is tightly screwed to the two pistons 67. One of the two screwedconnections is illustrated in FIG. 7 which shows the cross-section ofthe expanding mandrel 62. This figure also shows that the pistons orclamping strips 67 guided in the chambers 68 are each sealed off bymeans of an O-ring (not shown).

In contrast to the prior art known from the initially described U.S.Patent Document U.S. Pat. No. 4,754,906, in the device 57 according tothe invention, the hydraulic chambers 68 in the support-sidehalf-mandrel 64 are each equipped with pistons 67 which are arranged inthem in a tightly and movably guided manner and which, as a result oftheir fixed connection (for example, screwed connection) with thebearing-cover-side half-mandrel 63, guide this half-mandrel in astraight line and operate it for the purpose of fracture separating.Thus, in the device 57, the pistons 67, which are arranged in a guidedmanner, form the combined operating/guiding linkage 66 which, togetherwith the hydraulic chambers 68, including the expanding mandrel 62,forms the fracture separating device 61. In this embodiment, one pistonrod is left out whose function is taken over by the respective piston67.

The springs 69, which act as elastically flexible stops 65, are used fora restoring of the bearing-cover-side half-mandrel 63 relative to thesupport-side half-mandrel 64 for the easy axial introduction of theexpanding mandrel 62 into the bearing bores of the bearing arrangements59.

FIG. 6 also shows that the support-side half-mandrel 64 is arrangedbetween adjacent bearing arrangements 59 while additionally interactingwith supporting elements 70 of a securing frame 71. In each supportingelement 70, the securing frame 71 has openings 72, which are widened inan oblong-hole-type manner and which catch the expanding mandrel 62after the fracture separating of the bearing covers 60. For therotational securing of the bearing covers 60, stops 73 are providedwhich can be displaced between the supporting elements 70 in thefracture-separating direction and which are each equipped with lockabletensioning elements 73' which grip a bearing cover 60 between its frontfaces in a tong-type manner. The securing frame 71 with the stops 73 isfixedly arranged on the stand side. For introducing the fractureseparating force in the predetermined fracture-separating direction, theexpanding mandrel 62 may be arranged in a rotationally secured mannerrelative to the crankcase 58 or to the stand which is not shown.

Within the framework of the invention, fracture separating devices whichare equipped with lugs in the combined operating/guiding linkage canfracture separate the bearing covers of the bearing arrangements also bymeans of pressure forces, in which case these lugs act, for example, onthe respective mandrel through the cylinder bores of a crankcase.

Furthermore, the invention can also be used for the common fractureseparating of several bearing covers of correspondingly arrangedconnecting rods.

A separately vertically adjustable arrangement of a respective crankcasewill not be necessary if the radius of the respective mandrel is clearlysmaller than that of the respective bearing bore of the bearingarrangements, maximally up to 5%.

Also, the fracture separating device according to the invention can beused in any spatial position.

Although the invention has been described and illustrated in detail, itis to be clearly understood that the same is by way of illustration andexample, and is not to be taken by way of limitation. The spirit andscope of the present invention are to be limited only by the terms ofthe appended claims.

We claim:
 1. Device for fracture separating bearing covers of alignedbearing bores in bearing arrangements of a machine member, comprising:amandrel having an at least partially circular cross-section to be guidedas a separating element axially in the bearing bores, an operatinglinkage operatively connected with the mandrel via a plurality of lugshaving lug openings to be aligned with said bearing bores, said lugopenings receiving said mandrel, said operating linkage beingoperatively connected with an energy accumulator to impart a fractureseparating force on the bearing cover in a direction transverse to alongitudinal course of the mandrel via said lugs and said mandrel, theenergy accumulator being a piston-cylinder unit with a piston rodforming a section of the operating linkage, the piston rod of theoperating linkage being guided in a straight line on the cylinder sideand being used for guiding the respective mandrel in a fractureseparating direction, the respective mandrel being held in arotationally secured manner and each bearing cover being rotationallysecured while being clamped against the mandrel.
 2. Device according toclaim 1,wherein a piston of the piston-cylinder unit is initiallyhydraulically acted upon for a prestressing force of approximately 70 to90% of the fracture separating force, the piston being subsequentlyacted upon in an intensified manner for causing an abruptly effectivefracture separating force.
 3. Device according to claim 1, wherein theoperating linkage and the energy accumulator are arranged in a standwhich is constructed with at least one receiving device used for apositioned arrangement of the respective machine member relative to thefracture separating device.
 4. Device according to claim 3, wherein thestand with its receiving device is used for a support of a crankcase ofa piston engine having bearing arrangements, said support supporting thefracture separating force,stops being provided on the lugs which engagethe bearing covers to prevent rotation thereof.
 5. Device according toclaim 4,wherein the full mandrel is axially positioned by means of astop, and is axially secured in position during fracture separating bymeans of a clamped holding of at least one bearing bore of the bearingarrangements.
 6. Device according to claim 4,wherein the full mandrel,which is provided for fracture separating a predetermined number ofbearing covers, has profiles in a bearing-cover-side circumferentialarea which are adapted to a time-varied fracture separating ofpredetermined bearing covers, the full mandrel being axially secured inposition by means of clamping holding devices which operate in severalbearing bores.
 7. Device according to claim 3,wherein the stand isconstructed with a receiving device for the crankcase, which receivingdevice is vertically adjustable relative to the respective fractureseparating device, the vertical adjustment being controlled by way of anadjusting device serving to align the bearing arrangements of thecrankcase with respect to the mandrel openings in at least one of thelugs and the supporting elements, for a non-clamping sliding-in of themandrel.
 8. Device according to claim 7, wherein the stand has receivingdevices for the crankcase which are arranged to be movable transverselyto the fracture separating direction.
 9. Device according to claim 1,wherein said bearing covers comprise a bearing cover compound framewhich includes several bearing covers.
 10. Device according to claim 1,further comprising auxiliary screws with arranged in the bearingarrangements spaced away from the bearing covers with respect to a freeflow of the fracture separating.
 11. Apparatus for fracture separating abearing cover from a component having a bearing arrangement defining abearing bore, comprising:a pair of lugs to be arranged on mutuallyopposite sides of said bearing bore, each of said lugs defining a lugopening to be aligned with said bearing bore along an axis; a mandrel tobe inserted axially through said lug openings and said bearing bore,said lugs and said mandrel being movable in a direction transverse tosaid axis; a receiving device engaging said component to preventmovement thereof at least in said transverse direction; and an energyaccumulator operatively coupled to said pair of lugs to move said lugsand said mandrel in said transverse direction to fracture said bearingcover from said component.
 12. Apparatus according to claim 11, furthercomprising mandrel holding means for holding the mandrel in arotationally secure manner during said force fracture separation. 13.Apparatus according to claim 11, further comprising bearing coverholding means carried by the mandrel and serving to rotationally securethe bearing cover with respect to the mandrel during fracture separationmovement of the bearing cover.
 14. Apparatus for fracture separating abearing cover from a component having at least one bearing arrangementdefining at least one bearing bore, respectively, comprising:a pluralityof lugs, each of said lugs defining a lug opening to be aligned withsaid at least one bearing bore along an axis; a mandrel to be insertedaxially through said lug openings and said at least one bearing bore,said lugs and at least a portion of said mandrel being movable in adirection transverse to said axis; a receiving device which supportssaid component from movement at least in said transverse direction; andan energy accumulator operatively coupled to said lugs to move said lugsand said at least a portion of said mandrel in said transverse directionto fracture said bearing cover from said component.
 15. Apparatusaccording to claim 14, further comprising mandrel holding means forholding the mandrel in a rotationally secure manner during said forcefracture separation.
 16. Apparatus according to claim 14, furthercomprising bearing cover holding means carried by the mandrel andserving to rotationally secure the bearing cover with respect to themandrel during fracture separation movement of the bearing cover.